Field of the Invention
The present invention relates to an impact energy absorbing propeller shaft. More particularly, the present invention relates to an impact energy absorbing propeller shaft capable of absorbing and reducing impact energy at the time of a collision accident of a vehicle.
Description of Related Art
A propeller shaft mounted in a vehicle is a component that is positioned between a transmission (or transfer) and a rear differential of a vehicle to transmit power of an engine, and used to transmit power to rear wheels of a four-wheel-drive or rear-wheel-drive vehicle.
A general propeller shaft in the related art includes a front tube (or front shaft) which is connected, by means of a joint, to the transmission to which power of the engine is input, and a rear tube (or rear shaft) which is connected, by means of a joint, to the rear differential that transmits power to the rear wheel, and the front tube and the rear tube are connected by a constant velocity joint.
Recently, as safety in respect to a vehicle collision is considered important, various efforts have been devoted to reduce a collapse load of the propeller shaft and improve collision performance.
The propeller shaft, which serves to transmit power at normal times, is deformed by impact energy that is applied in an axial direction at the time of a collision accident in a front and rear direction of the vehicle, and damages the main components of the vehicle or causes an injury to a body of an occupant. Therefore, recently, a propeller shaft having a function of absorbing impact energy is applied to a number of vehicles in order to prevent damage to components and injuries to occupants at the time of a collision accident of the vehicle.
As the propeller shaft having a function of absorbing impact energy, a propeller shaft with a swaging tube structure is typically and mainly used.
FIG. 1 illustrates the propeller shaft with a swaging tube structure in the related art. The propeller shaft 1, similar to the related art, has a swaged tube portion 2 which is formed at one side of the propeller shaft 1 and has a diameter that is reduced by a swaging process. Therefore, the swaged tube portion 2 is pushed into a non-swaged tube portion 3 with a non-reduced diameter at the time of a collision accident, thereby absorbing impact energy.
However, the propeller shaft in the related art having the aforementioned function of absorbing impact energy has problems in that time and costs required to perform a process of forming the swaging tube structure are increased, and strength of the propeller shaft deteriorates due to stress concentration caused by plastic swaging processing.
In order to solve the above problems, a technology regarding a propeller shaft, which has a tube structure that is coupled by using a shear pin and allows the shear pin to be broken at the time of a collision so as to absorb impact energy, has been proposed in the related art.
However, the propeller shaft in the related art, which has the aforementioned function of absorbing impact energy at the time of a collision accident of the vehicle, is not satisfactory in terms of the number of components and a collapse load, and as a result, the continuous development of the propeller shaft is required.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.